1. Field of the Invention
The present invention relates to hinges and more particularly, to a durable hinge that provides a variable torque.
2. Description of Related Art
FIG. 1 is an exploded view of a hinge according to the prior art. In FIG. 1, the hinge comprises a male hinge member 11 and a female hinge member 12. The male hinge member 11 has an end wall 111, a shaft 13 perpendicularly extending from the end wall 111, and a mounting portion 14 disposed at the other end remote from the shaft 13. The female hinge member 12 has an end wall 121, a sleeve 15 formed through the end wall 121, and a mounting portion 16 disposed at the other end remote from the end wall 121. Further, the end wall 111 of the male hinge member 11 has protruding blocks 112 and 113. The end wall 121 of the female hinge member 12 has protruding blocks 122 and 123.
During the operation of the traditional hinge, the shaft 13 of the male hinge member 11 is inserted into the sleeve 15 of the female hinge member 12, keeping the end wall 111 of the male hinge member 11 in contact with the end wall 121 of the female hinge member 12. When rotating the male hinge member 11 relative to the female hinge member 12, the protruding blocks 112 and 113 of the male hinge member 11 will be forced against the protruding blocks 122 and 123 of the female hinge member 12 subject to the angle of rotation of the male hinge member 11 relative to the female hinge member 12. When the protruding blocks 112 and 113 of the male hinge member 11 are stopped against the protruding blocks 122 and 123 of the female hinge member 12, the positive pressure (friction pressure) between the male hinge member 11 and the female hinge member 12 is relatively great so that the hinge provides a relatively great torsional force. On the other hand, when the protruding blocks 112 and 113 of the male hinge member 11 and the protruding blocks 122 and 123 of the female hinge member 12 are set apart, the positive pressure (friction pressure) between the male hinge member 11 and the female hinge member 12 is relatively small so that the hinge provides a relatively small torsional force. According to this design, the hinge according to the prior art provides different torsional force by means of changing the forward pressure (friction pressure) between the male hinge member 11 and the female hinge member 12, i.e., changing the relative position between the protruding blocks 112 and 113 of the male hinge member 11 and the protruding blocks 122 and 123 of the female hinge member 12. Therefore, the hinge according to the prior art provides different torque when the male hinge member 11 is rotated at different angles relative to the female hinge member 12.
However, this design does not allow smooth rotation of the male hinge member 11 relative to the female hinge member 12. Further, frequently changing the positive pressure (friction pressure) between the male hinge member 11 and the female hinge member 12 inevitably causes the protruding blocks 112 and 113 of the male hinge member 11 and the protruding blocks 122 and 123 of the female hinge member 12 to wear quickly. Once the protruding blocks 112 and 113 of the male hinge member 11 and the protruding blocks 122 and 123 of the female hinge member 12 start to wear, the hinge having the male hinge member 11 and the female hinge member 12 will be unable to function well.